getoptcvt

Synopsis

Description

/usr/lib/getoptcvt reads the shell script in filename, converts it to use getopts
instead of getopt, and writes the results on the standard output.

getopts is a built-in Bourne shell command used to parse positional parameters and
to check for valid options. See sh(1). It supports all applicable rules
of the command syntax standard (see Rules 3-10, Intro(1)). It should be used in
place of the getopt command. (See the NOTES section below.) The syntax for
the shell's built-in getopts command is:

getoptsoptstringname [ argument . . . ]

optstring must contain the option letters the command using getopts will recognize; if
a letter is followed by a colon (:), the option is expected to have
an argument, or group of arguments, which must be separated from it by
white space.

Each time it is invoked, getopts places the next option in the shell
variable name and the index of the next argument to be processed in
the shell variable OPTIND. Whenever the shell or a shell script is
invoked, OPTIND is initialized to 1.

When an option requires an option-argument, getopts places it in the shell variable
OPTARG.

If an illegal option is encountered, ? will be placed in name.

When the end of options is encountered, getopts exits with a non-zero exit
status. The special option -- may be used to delimit the end
of the options.

By default, getopts parses the positional parameters. If extra arguments (argument . . .) are given
on the getopts command line, getopts parses them instead.

So that all new commands will adhere to the command syntax standard described
in Intro(1), they should use getopts or getopt to parse positional parameters and check
for options that are valid for that command (see the NOTES section below).

Options

The following option is supported:

-b

Makes the converted script portable to earlier releases of the UNIX system. /usr/lib/getoptcvt modifies the shell script in filename so that when the resulting shell script is executed, it determines at run time whether to invoke getopts or getopt.

Examples

Example 1 Processing the arguments for a command

The following fragment of a shell program shows how one might process the
arguments for a command that can take the options -a or -b, as
well as the option -o, which requires an option-argument:

See Also

Diagnostics

getopts prints an error message on the standard error when it encounters an
option letter not included in optstring.

Notes

Although the following command syntax rule (see Intro(1)) relaxations are permitted under the
current implementation, they should not be used because they may not be supported
in future releases of the system. As in the EXAMPLES section above, -a
and -b are options, and the option -o requires an option-argument. The following
example violates Rule 5: options with option-arguments must not be grouped with
other options:

example% cmd -aboxxx filename

The following example violates Rule 6: there must be white space after an
option that takes an option-argument:

example% cmd -ab oxxx filename

Changing the value of the shell variable OPTIND or parsing different sets of
arguments may lead to unexpected results.